/*
 * Copyright (C) 2009 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef PINYINIME_INCLUDE_SPELLINGTABLE_H__
#define PINYINIME_INCLUDE_SPELLINGTABLE_H__

#include <stdlib.h>
#include "./dictdef.h"

namespace ime_pinyin {

#ifdef ___BUILD_MODEL___

    const Size_t kMaxSpellingSize = kMaxPinyinSize;

    typedef struct {
        char str[kMaxSpellingSize + 1];
        double freq;
    } RawSpelling, *PRawSpelling;

    // This class is used to store the spelling strings
    // The length of the input spelling string should be less or equal to the
    // spelling_size_ (set by init_table). If the input string is too long,
    // we only keep its first spelling_size_ chars.
    class SpellingTable {
        private:
            static const Size_t kNotSupportNum = 3;
            static const char kNotSupportList[kNotSupportNum][kMaxSpellingSize + 1];

            bool need_score_;

            Size_t spelling_max_num_;

            RawSpelling *raw_spellings_;

            // Used to store spelling strings. If the spelling table needs to calculate
            // score, an extra char after each spelling string is the score.
            // An item with a lower score has a higher probability.
            char *spelling_buf_;
            int spelling_size_;

            double total_freq_;

            Size_t spelling_num_;

            double score_amplifier_;

            unsigned char average_score_;

            // If frozen is true, put_spelling() and contain() are not allowed to call.
            bool frozen_;

            Size_t get_hash_pos ( const char *spelling_str );
            Size_t hash_pos_next ( Size_t hash_pos );
            void free_resource();
        public:
            SpellingTable();
            ~SpellingTable();

            // pure_spl_size is the pure maximum spelling string size. For example,
            // "zhuang" is the longgest item in Pinyin, so pure_spl_size should be 6.
            // spl_max_num is the maximum number of spelling strings to store.
            // need_score is used to indicate whether the caller needs to calculate a
            // score for each spelling.
            bool init_table ( Size_t pure_spl_size, Size_t spl_max_num, bool need_score );

            // Put a spelling string to the table.
            // It always returns false if called after arrange() withtout a new
            // init_table() operation.
            // freq is the spelling's occuring count.
            // If the spelling has been in the table, occuring count will accumulated.
            bool put_spelling ( const char *spelling_str, double spl_count );

            // Test whether a spelling string is in the table.
            // It always returns false, when being called after arrange() withtout a new
            // init_table() operation.
            bool contain ( const char *spelling_str );

            // Sort the spelling strings and put them from the begin of the buffer.
            // Return the pointer of the sorted spelling strings.
            // item_size and spl_num return the item size and number of spelling.
            // Because each spelling uses a '\0' as terminator, the returned item_size is
            // at least one char longer than the spl_size parameter specified by
            // init_table(). If the table is initialized to calculate score, item_size
            // will be increased by 1, and current_spl_str[item_size - 1] stores an
            // unsinged char score.
            // An item with a lower score has a higher probability.
            // Do not call put_spelling() and contains() after arrange().
            const char *arrange ( Size_t *item_size, Size_t *spl_num );

            float get_score_amplifier();

            unsigned char get_average_score();
    };
#endif  // ___BUILD_MODEL___
}

#endif  // PINYINIME_INCLUDE_SPELLINGTABLE_H__
